The National Geographic Coarse Foam Pads help maintain a healthy, thriving aquarium. The quality coarse foam pads are used for mechanical and biological filtration. Can be rinsed and reused. Only at PetSmart. Features: Can be rinsed and reused Includes: 2 Foam Pads Intended For: Aquarium Health Consideration: Create a thriving aquarium Compatible With: NG130, NG140, NG150 internal filters Caution: This is not a toy. Contains small parts. Keep out of reach of children. To avoid injury, follow safety instructions in the enclosed instruction guide. Instructions: To help maintain a healthy aquarium, change the white pads every 3-6 months, and change the blue pad every year or when it loses shape. Change out 10% of the water weekly or 25% monthly. Use a water conditioner every time you add fresh tap water to your aquarium. Be sure your bucket is only used for aquarium water. Never use soap, detergents or cleaning agents while cleaning the aquarium or equipment as they can harm your fish.